Use of Cardiac Resynchronization Therapy Among Eligible Patients Receiving an Implantable Cardioverter Defibrillator: Insights From the National Cardiovascular Data Registry Implantable Cardioverter Defibrillator Registry

Negative effects of COVID-19 on the implantation rate of cardiac resynchronization therapy with defibrillator device

Introduction

COVID-19 drastically impacted the landscape of the United States' medical system. Limited data is available on the nationwide implantation trends in Cardiac Resynchronization Therapy Defibrillator (CRT-D) devices before and during the pandemic. We aimed to explore the impact of the COVID-19 pandemic on CRT-D insertion rates and adverse outcomes related to delays in care.

Methods and Results

We conducted a retrospective cross-sectional analysis using the National Inpatient Sample database between 2017 and 2020. Variables were identified using their ICD-10 codes. Inclusion criteria: age ≥ 18 years, presenting for a nonelective admission, primary diagnosis of hypertensive heart disease, hypertensive heart, chronic kidney disease, or heart failure, and underwent insertion of a CRT-D. Between 2017 and 2020, CRT-D devices were inserted during 23,635 admissions. On average, 6198 devices were implanted yearly from 2017 to 2019, with only 5040 devices being implanted in 2020. Additionally, reduced implantation rates were noted for every cohort of hospital size, location, and teaching status during this year. The year 2020 also had the highest average death rate at 1.39%, but this difference was statistically insignificant (adjusted Wald test p = .767), and COVID-19 was not associated with an increased risk of inpatient mortality (OR 0.22, 95% CI 0.03-1.82, p = .162).

Conclusion

The COVID-19 pandemic has affected all facets of the healthcare system, especially surgical volume rates. CRT-D procedures significantly decreased in 2020. This is the first retrospective study highlighting the trend of reduced rates of CRT-D implantation as a response to the COVID-19 pandemic.

Paving a Path to Equity in Cardiorenal Care

Cardiorenal syndrome encompasses a dynamic interplay between cardiovascular and kidney disease, and its prevention requires careful examination of multiple predisposing underlying conditions. The unequal distribution of diabetes, heart failure, hypertension, and kidney disease requires special attention because of the influence of these conditions on cardiorenal disease. Despite growing evidence regarding the benefits of disease-modifying agents (e.g., sodium-glucose cotransporter 2 inhibitors) for cardiovascular, kidney, and metabolic (CKM) disease, significant disparities remain in access to and utilization of these essential therapeutics. Multilevel barriers impeding their use require multisector interventions that address patient, provider, and health system-tailored strategies. Burgeoning literature also describes the critical role of unequal social determinants of health, or the sociopolitical contexts in which people live and work, in cardiorenal risk factors, including heart failure, diabetes, and chronic kidney disease. This review outlines (i) inequality in the burden and treatment of hypertension, type 2 diabetes, and heart failure; (ii) disparities in the use of key disease-modifying therapies for CKM diseases; and (iii) multilevel barriers and solutions to achieve greater pharmacoequity in the use of disease-modifying therapies. In addition, this review provides summative evidence regarding the role of unequal social determinants of health in cardiorenal health disparities, further outlining potential considerations for future research and intervention. As proposed in the 2023 American Heart Association presidential advisory on CKM health, a paradigm shift will be needed to achieve cardiorenal health equity. Through a deeper understanding of CKM health and a commitment to equity in the prevention, detection, and treatment of CKM disease, we can achieve this critical goal.

Achieving Health Equity in the Care of Patients with Heart Failure

PURPOSE OF REVIEW

To discuss the prevailing racial and ethnic disparities in heart failure (HF) care by identifying barriers to equitable care and proposing solutions for achieving equitable outcomes.

RECENT FINDINGS

Throughout the entire spectrum of HF care, from prevention to implementation of guideline-directed medical therapy and advanced interventions, racial and ethnic disparities exist. Factors such as differential distribution of risk factors, poor access to care, inadequate representation in clinical trials, and discrimination from healthcare clinicians, among others, contribute to these disparities. Recent data suggests that despite improvements, disparities prevail in several aspects of HF care, hindering our progress towards equity in HF care. This review highlights the urgent need to address racial and ethnic disparities in HF care, emphasizing the importance of a multifaceted approach involving policy changes, quality improvement strategies, targeted interventions, and intentional community engagement. Our proposed framework was derived from existing research and emphasizes integrating equity into routine quality improvement efforts, tailoring interventions to specific populations, and advocating for policy transformation. By acknowledging these disparities, implementing evidence-based strategies, and fostering collaborative efforts, the HF community can strive to reduce disparities and achieve equity in HF care.

Variation in hospital use of cardiac resynchronization therapy-defibrillator among eligible patients and association with clinical outcomes

BACKGROUND

Despite strong guideline recommendations for cardiac resynchronization therapy-defibrillator (CRT-D) In select patients, this therapy is underutilized with substantial variation among hospitals, and the association of this variation with outcomes is unknown.

OBJECTIVE

To assess if facility variation in CRT-D utilization is associated with differences in hospital-level outcomes METHODS: We linked Medicare claims data with the NCDR ICD Registry from 2010 to 2015. We assessed the intraclass correlation coefficient to quantify the degree of variation in patient-level CRT usage that can be explained by interfacility variation on a hospital level. To quantify the degree of hospital variation in patient-level outcomes (all-cause mortality, readmissions, and cardiac readmissions) that can be attributed to variations in CRT-D usage, we utilized multi-level modeling.

RESULTS

The study included 30,134 patients across 1,377 hospitals. The median rate of CRT-D implantation among those meeting guideline indications was 89%, but there was a wide variation across hospitals. After adjustment, most of the variation (74%) in hospital rates of CRT-D utilization was attributable to the hospital in which the patient was treated. Differences in hospital CRT-D utilization was associated with 8.76%, 5.26%, and 4.71% of differences in hospital mortality, readmissions, and cardiac readmission rates, respectively (p<0.001 for all outcomes).

CONCLUSIONS

There is wide variation in the use of CRT-D across hospitals that was not explained by case mix. Hospital-level variation in CRT-D utilization was associated with clinically significant differences in outcomes. A measure of CRT-D utilization in eligible patients may serve as a useful metric for quality improvement efforts.

Omecamtiv Mecarbil in Black Patients With Heart Failure and Reduced Ejection Fraction: Insights From GALACTIC-HF

BACKGROUND

Omecamtiv mecarbil improves cardiovascular outcomes in patients with heart failure (HF) with reduced ejection fraction (EF). Consistency of drug benefit across race is a key public health topic.

OBJECTIVES

The purpose of this study was to evaluate the effect of omecamtiv mecarbil among self-identified Black patients.

METHODS

In GALACTIC-HF (Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure) patients with symptomatic HF, elevated natriuretic peptides, and left ventricular ejection fraction (LVEF) ≤35% were randomized to omecamtiv mecarbil or placebo. The primary outcome was a composite of time to first event of HF or cardiovascular death. The authors analyzed treatment effects in Black vs White patients in countries contributing at least 10 Black participants.

RESULTS

Black patients accounted for 6.8% (n = 562) of overall enrollment and 29% of U.S. enrollment. Most Black patients enrolled in the United States, South Africa, and Brazil (n = 535, 95%). Compared with White patients enrolled from these countries (n = 1,129), Black patients differed in demographics, comorbid conditions, received higher rates of medical therapy and lower rates of device therapies, and experienced higher overall event rates. The effect of omecamtiv mecarbil was consistent in Black vs White patients, with no difference in the primary endpoint (HR = 0.83 vs 0.88, P-interaction = 0.66), similar improvements in heart rate and N-terminal pro-B-type natriuretic peptide, and no significant safety signals. Among endpoints, the only nominally significant treatment-by-race interaction was the placebo-corrected change in blood pressure from baseline in Black vs White patients (+3.4 vs -0.7 mm Hg, P-interaction = 0.02).

CONCLUSIONS

GALACTIC-HF enrolled more Black patients than other recent HF trials. Black patients treated with omecamtiv mecarbil had similar benefit and safety compared with White counterparts.

Variation in regional implantation patterns of cardiac implantable electronic device in Switzerland

Introduction

There is a substantial geographical variation in the rates of pacemaker (PM), implantable cardioverter defibrillator (ICD), and cardiac resynchronization therapy (CRT) device implantation across European countries. We assessed the extent of regional variation and potential determinants of such variation.

Methods

We conducted a population-based analysis using discharge data for PM/ICD/CRT implantations from all Swiss acute care hospitals during 2013–2016. We derived hospital service areas (HSA) by analyzing patient flows. We calculated age- and sex-standardized rates and quantified variation using the extremal quotient (EQ) and the systemic component of variation (SCV). We estimated the reduction in variance of crude implantation rates across HSAs using multilevel regression models, with incremental adjustment for age and sex, language, socioeconomic factors, population health, diabetes mellitus, and the density of cardiologists on the HSA level.

Results

We analyzed implantations of 8129 PM, 1461 ICD, and 1411 CRT from 25 Swiss HSAs. The mean age- and sex-standardized implantation rate was 29 (range 8–57) per 100,000 persons for PM, 5 (1–9) for ICD, and 5 (2–8) for CRT. There was a very high variation in PM (EQ 7.0; SCV 12.6) and ICD (EQ 7.2; SCV 11.3) and a high variation in CRT implantation rates (EQ 3.9; SCV 7.1) across HSAs. Adjustments for age and sex, language, socioeconomic factors, population health, diabetes mellitus, and density of cardiologists explained 94% of the variance in ICD and 87.5% of the variance in CRT implantation rates, but only 36.3% of the variance in PM implantation rates. Women had substantially lower PM/ICD/CRT implantation rates than men.

Conclusion

Switzerland has a very high regional variation in PM/ICD implantation and a high variation in CRT implantation rates. Women had substantially lower implantation rates than men. A large share of the variation in PM procedure rates remained unexplained which might reflect variations in physicians’ preferences and practices.

Importance of electromagnetic interactions between ICD and VAD devices - mechanistic assessment

BACKGROUND

Implanted cardioverter defibrillators (ICD) and Left Ventricular Assist Devices (LVAD) are established interventions that prolong life in advanced heart failure, but their combination has not been demonstrated as beneficial. Electromagnetic interference (EMI) produced by a LVAD can preclude ICD interrogation with external programmers. We undertook a systematic evaluation of the LVAD-ICD interaction "in-vitro" to clarify the extent of this interaction.

METHODS

Using explanted ICDs and VADs in a mock physiological rig, we assessed interrogation and reprogramming of ICD devices in the presence of a running LVAD. When connectivity between the ICD programmer and the ICD failed, we attempted three different techniques to re-establish connectivity: (1) Electromagnetic shielding of the ICD with a pseudo-faraday cage; (2) altering the LVAD speed; (3) increasing the distance between the VAD and the ICD.

RESULTS

We tested a total of 24 ICDs from different manufacturers in the presence of the Heartware (HW) and HeartMate 3 (HM3) LVADs. With HW, we only observed interaction with Biotronik ICD-devices at very close range (0-6cm). With HM3, only Medtronic ICD devices showed no interaction. Interactions could be mitigated byincreasing the VAD-ICD distance.

CONCLUSIONS

LVADs, notably the HM3, produce EMI that interferes with the communication between an ICD and it's respective programmer. This may need to be considered when choosing the type of VAD to implant in patients with a previously implanted left-sided ICD. The only safe way to regain connectivity is to increase the distance between the VAD and the ICD, with patients raising their arm above their head.

Association Between Patient Survival and Clinician Variability in Treatment Rates for Aortic Valve Stenosis

Background Patients with symptomatic severe aortic stenosis (ssAS) have a high mortality risk and compromised quality of life. Surgical/transcatheter aortic valve replacement (AVR) is a Class I recommendation, but it is unclear if this recommendation is uniformly applied. We determined the impact of managing cardiologists on the likelihood of ssAS treatment. Methods and Results Using natural language processing of Optum electronic health records, we identified 26 438 patients with newly diagnosed ssAS (2011-2016). Multilevel, multivariable Fine-Gray competing risk models clustered by cardiologists were used to determine the impact of cardiologists on the likelihood of 1-year AVR treatment. Within 1 year of diagnosis, 35.6% of patients with ssAS received an AVR; however, rates varied widely among managing cardiologists (0%, lowest quartile; 100%, highest quartile [median, 29.6%; 25th-75th percentiles, 13.3%-47.0%]). The odds of receiving AVR varied >2-fold depending on the cardiologist (median odds ratio for AVR, 2.25; 95% CI, 2.14-2.36). Compared with patients with ssAS of cardiologists with the highest treatment rates, those treated by cardiologists with the lowest AVR rates experienced significantly higher 1-year mortality (lowest quartile, adjusted hazard ratio, 1.22, 95% CI, 1.13-1.33). Conclusions Overall AVR rates for ssAS were low, highlighting a potential challenge for ssAS management in the United States. Cardiologist AVR use varied substantially; patients treated by cardiologists with lower AVR rates had higher mortality rates than those treated by cardiologists with higher AVR rates.

Use and Outcomes of Dual Chamber or Cardiac Resynchronization Therapy Defibrillators Among Older Patients Requiring Ventricular Pacing in the National Cardiovascular Data Registry Implantable Cardioverter Defibrillator Registry

IMPORTANCE

Frequent right ventricular (RV) pacing can cause and exacerbate heart failure. Cardiac resynchronization therapy (CRT) has been shown to be associated with improved outcomes among patients with reduced left ventricular ejection fraction who need frequent RV pacing, but the patterns of use of CRT vs dual chamber (DC) devices and the associated outcomes among these patients in clinical practice is not known.

OBJECTIVE

To assess outcomes, variability in use of device type, and trends in use of device type over time among patients undergoing implantable cardioverter defibrillator (ICD) implantation who were likely to require frequent RV pacing but who did not have a class I indication for CRT.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used the National Cardiovascular Data Registry (NCDR) ICD Registry. A total of 3100 Medicare beneficiaries undergoing first-time implantation of CRT defibrillator (CRT-D) or DC-ICD from 2010 to 2016 who had a class I or II guideline ventricular bradycardia pacing indication but not a class I indication for CRT were included. Data were analyzed from August 2018 to October 2019.

EXPOSURES

Implantation of a CRT-D or DC-ICD.

MAIN OUTCOMES AND MEASURES

All-cause mortality, heart failure hospitalization, and complications were ascertained from Medicare claims data. Multivariable Cox proportional hazards models and Fine-Gray models were used to evaluate 1-year mortality and heart failure hospitalization, respectively. Multivariable logistic regression was used to evaluate 30-day and 90-day complications. All models accounted for clustering. The median odds ratio (MOR) was used to assess variability and represents the odds that a randomly selected patient receiving CRT-D at a hospital with high implant rates would receive CRT-D if they had been treated at a hospital with low CRT-D implant rates.

RESULTS

A total of 3100 individuals were included. The mean (SD) age was 76.3 (6.4) years, and 2500 (80.6%) were men. The 1698 patients (54.7%) receiving CRT-D were more likely than those receiving DC-ICD to have third-degree atrioventricular block (828 [48.8%] vs 432 [30.8%]; P < .001), nonischemic cardiomyopathy (508 [29.9%] vs 255 [18.2%]; P < .001), and prior heart failure hospitalizations (703 [41.4%] vs 421 [30.0%]; P < .001). Following adjustment, CRT-D was associated with lower 1-year mortality (hazard ratio [HR], 0.70; 95% CI, 0.57-0.87; P = .001) and heart failure hospitalization (subdistribution HR, 0.77; 95% CI, 0.61-0.97; P = .02) and no difference in complications compared with DC-ICD. Hospital variation in use of CRT was present (MOR, 2.00), and the use of CRT in this cohort was higher over time (654 of 1351 [48.4%] in 2010 vs 362 of 594 [60.9%] in 2016; P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study of older patients in contemporary practice undergoing ICD implantation with a bradycardia pacing indication but without a class I indication for CRT, CRT-D was associated with better outcomes compared with DC devices. Variability in use of device type was observed, and the rate of CRT implantation increased over time.

Effects of dapagliflozin in DAPA-HF according to background heart failure therapy

AIMS

In the DAPA-HF trial, the SGLT2 inhibitor dapagliflozin reduced the risk of worsening heart failure (HF) and death in patients with HF and reduced ejection fraction. We examined whether this benefit was consistent in relation to background HF therapy.

METHODS AND RESULTS

In this post hoc analysis, we examined the effect of study treatment in the following yes/no subgroups: diuretic, digoxin, mineralocorticoid receptor antagonist (MRA), sacubitril/valsartan, ivabradine, implanted cardioverter-defibrillating (ICD) device, and cardiac resynchronization therapy. We also examined the effect of study drug according to angiotensin-converting enzyme inhibitor/angiotensin receptor blocker dose, beta-blocker (BB) dose, and MRA (≥50% and <50% of target dose). We analysed the primary composite endpoint of cardiovascular death or a worsening HF event. Most randomized patients (n = 4744) were treated with a diuretic (84%), renin-angiotensin system (RAS) blocker (94%), and BB (96%); 52% of those taking a BB and 38% taking a RAS blocker were treated with ≥50% of the recommended dose. Overall, the dapagliflozin vs. placebo hazard ratio (HR) was 0.74 [95% confidence interval (CI) 0.65-0.85] for the primary composite endpoint (P < 0.0001). The effect of dapagliflozin was consistent across all subgroups examined: the HR ranged from 0.57 to 0.86 for primary endpoint, with no significant randomized treatment-by-subgroup interaction. For example, the HR in patients taking a RAS blocker, BB, and MRA at baseline was 0.72 (95% CI 0.61-0.86) compared with 0.77 (95% CI 0.63-0.94) in those not on all three of these treatments (P-interaction 0.64).

CONCLUSION

The benefit of dapagliflozin was consistent regardless of background therapy for HF.

Cardiac resynchronization therapy with a defibrillator (CRTd) in failing heart patients with type 2 diabetes mellitus and treated by glucagon-like peptide 1 receptor agonists (GLP-1 RA) therapy vs. conventional hypoglycemic drugs: arrhythmic burden, hospitalizations for heart failure, and CRTd responders rate

Objectives

To evaluate clinical outcomes in patients with diabetes, treated by cardiac resynchronization therapy with a defibrillator (CRT-d), and glucagon-like peptide 1 receptor agonists (GLP-1 RA) in addition to conventional hypoglycemic therapy vs. CRTd patients under conventional hypoglycemic drugs.

Background

Patients with diabetes treated by CRTd experienced an amelioration of functional New York Association Heart class, reduction of hospital admissions, and mortality, in a percentage about 60%. However, about 40% of CRTd patients with diabetes experience a worse prognosis.

Materials and methods

We investigated the 12-months prognosis of CRTd patients with diabetes, previously treated with hypoglycemic drugs therapy (n 271) vs. a matched cohort of CRTd patients with diabetes treated with GLP-1 RA in addition to conventional hypoglycemic therapy (n 288).

Results

At follow up CRTd patients with diabetes treated by GLP-1 RA therapy vs. CRTd patients with diabetes that did not receive GLP-1 RA therapy, experienced a significant reduction of NYHA class (p value < 0.05), associated to higher values of 6 min walking test (p value < 0.05), and higher rate of CRTd responders (p value < 0.05). GLP-1 RA patients vs. controls at follow up end experienced lower AF events (p value < 0.05), lower VT events (p value < 0.05), lower rate of hospitalization for heart failure worsening (p value < 0.05), and higher rate of CRTd responders (p value < 0.05). To date, GLP-1 RA therapy may predict a reduction of AF events (HR 0.603, CI [0.411–0.884]), VT events (HR 0.964, CI [0.963–0.992]), and hospitalization for heart failure worsening (HR 0.119, CI [0.028–0.508]), and a higher CRT responders rate (HR 3.707, CI [1.226–14.570]).

Conclusions

GLP-1 RA drugs in addition to conventional hypoglycemic therapy may significantly reduce systemic inflammation and circulating BNP levels in CRTd patients with diabetes, leading to a significant improvement of LVEF and of the 6 min walking test, and to a reduction of the arrhythmic burden. Consequently, GLP-1 RA drugs in addition to conventional hypoglycemic therapy may reduce hospital admissions for heart failure worsening, by increasing CRTd responders rate.

Trial registration NCT03282136. Registered 9 December 2017 “retrospectively registered”

Cardiac resynchronization therapy: A comparative analysis of mortality in African Americans and Caucasians

BACKGROUND

Cardiac resynchronization therapy (CRT) is recommended in patients with heart failure, reduced left ventricular ejection fraction, and a prolonged QRS duration. African Americans are underrepresented in clinical trials and CRT is underutilized; consequently, the benefits and outcomes of CRT are not well-defined.

METHODS

We evaluated 294 patients, determined survival using Kaplan-Meier analysis, and used Cox proportional hazards regression model to determine predictors of mortality. Propensity score-match analysis was applied to balance covariates in African Americans and Caucasians.

RESULTS

The mean age for African Americans (n  =  131) and Caucasians (n  =  163) was 65 ± 12 and 70 ± 13 years (P  =  0.0003). Mortality in African Americans was 28% compared to 37% in Caucasians (P  =  0.14) over a median follow-up of 8.1 ± 0.6 years. Survival was significantly reduced in African Americans and Caucasians with a glomerular filtration rate (GFR) < 60 (6.7 ± 0.4, 95% confidence interval [CI]: 5.9-7.5 vs 8.6 ± 0.5 CI: 7.7-9.5 years, P  =  0.005), and those not treated with an aldosterone antagonist (7.1 ± 0.4, 95% CI: 6.5-7.9 vs 8.7 ± 0.6, 7.6-9.9 years, P  =  0.04), respectively. Independent predictors of mortality were a GFR <60 and low left ventricular ejection fraction. In African Americans, ischemic cardiomyopathy (ICM) and lack of therapy with an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) were associated with increased mortality.

CONCLUSIONS

Long-term survival benefit from CRT was similar in African Americans and Caucasians. A GFR < 60 and lack of therapy with an aldosterone antagonist were associated with decreased survival. Survival also was inversely related to the number of comorbidities. In African Americans, underutilization of an ACEI or ARB, and ICM were additional factors associated with increased mortality.